The present invention relates generally to a drain assembly for a cooking appliance and, more particularly, to a drain assembly for diverting cooking effluent into a grease/water separator. The drain assembly can be downstream of the cooking appliance by a considerable amount, including outside of the building in which the cooking appliance is located. Also, the drain assembly can receive flows other than from a cooking appliance, including flows from other kitchen sources such as warewashing sinks.
A combination oven uses both steam and radiant heat in the cooking process. Typically, these ovens use a steam kettle to generate steam for the cooking chamber. The steam kettle must be periodically flushed to remove any limes, scales, or precipitate from the steam kettle. The flush cycle completely purges the water in the kettle by means of an internal pump or line pressure arrangement. This flush sequence can propel twenty to twenty-five liters of water through the kettle and into the combination oven. The flush water exits a discharge port in the oven in a short (30 to 60 second) time frame. These ovens typically use a condensate discharge pipe with an outer diameter of 50 millimeters. Therefore, the entire pipe cross section must be available to allow for such a high volume of water to be discharged in that time.
However, during the cooking process, condensed steam and grease exit the cooking area of the oven through the same discharge port in the oven as the flush water flow. This flow of condensed steam and grease exits at a much lower flow rate. It typically has been directed through the same drain line with its eventual discharge into a sewage outlet. In many applications, the grease tends to solidify within the drain pipe. Once that blockage occurs, the large flow of flush water cannot escape the drain pipe at a proper rate of speed. This backup may cause water to pool in the bottom of the appliance or leak out of the appliance through areas other than the drain. This backup may also cause contamination of the cooking racks and/or the food products placed on the cooking racks. Thus, there is a need to ensure that the drain pipe remains clear from any grease or other residue.
Further, the clogging of the drain pipe by the condensate from the cooking appliance causes drainage problems with other appliances connected to the drain pipe. Thus, there is a need to separate components of the condensate flow which could cause an obstruction within the drain pipe. In that regard, there is a need to divert the condensate to a grease/water separator or other pollution control device so that those components can be separated from the condensate stream thereby allowing a flow that is predominantly water to be discharged into the building""s drain system.
The present invention is directed to a drain assembly to be attached between the discharge port of a cooking appliance and the drain line for a building. The cooking appliance may be a combination oven. The drain assembly is designed so that low volume effluent will be diverted from the main flow channel of the assembly so that periodic high volume flows may flow unobstructed through the assembly.
Accordingly, one aspect of the invention is to provide an accumulator on a pipe. The pipe defines the main flow channel. The accumulator provides a path to which the low volume flow can be gravitationally diverted. The low volume flow will then be discharged through an exit port in the accumulator.
Another aspect of the invention is to reduce the likelihood that components of the low volume flow will obstruct the main flow channel. Thus, a heat source is located in proximity to the accumulator. The heat source is sufficient to melt any meltable components of that low volume flow, such as cooking grease.
The assembly of a first embodiment is typically cylindrical with an outer diameter of about 50 millimeters. The assembly is preferably made with 16 gauge bright finish stainless steel.
In an embodiment of the invention, the accumulator is attached to the pipe so that the accumulator spans across the lowest arc segment of the pipe. The accumulator may also be substantially cylindrical with its cross section having a diameter of about one inch. The accumulator preferably extends from the pipe for a depth of approximately 0.20 inches.
In order to ensure that all of the low volume flow is diverted, the accumulator of this embodiment is preferably has two extensions extending from its upper surface upward along opposite sides of the pipe. The width of the extensions may taper as they extend along the pipe. The exit port may be a circular hole with a diameter of about 0.75 inches centered in the lower end of the accumulator.
The second embodiment has a housing into which the main flow channel enters. The drain pipe discharges into the housing. Inside the housing, the lower periphery of the drain pipe is open and replaced with a strainer assembly. The drain pipe may also be terminated in the strainer assembly. The strainer assembly is typically U-shaped. The drain pipe begins again on a downstream end of the strainer assembly. The strainer conveyor assembly is perforated to allow liquid to be gravitationally diverted into the sump. The strainer assembly provides a sufficient bridge between the inlet and outlet to allow the passage of a high volume flow without substantial diversion of liquid into a sump located at the bottom of the housing. The strainer conveyor may be removable, with the provision of a handle. The sump has a suction line for transport of the diverted liquid to a grease-water separator. As with other embodiments, a heat source can be located near the strainer assembly in order to keep the perforations clear of congealed grease which could form an obstruction. In this embodiment, the heat source maintains the diverted liquid in a flowable state. Additionally, after removal of the grease, the diverted liquid can be returned into the housing to flow to the outlet.
The low volume flow may be conducted from accumulator into a grease/water separator such as a Big Dipper(copyright) oil/water separator marketed by Thermaco, Inc., of Asheboro, N.C. It may be preferable to conduct the low volume flow from the accumulator to the grease/water separator using a suction pump.
Understanding that the purpose of the assembly is to maintain the main flow channel free from obstruction, such as cooking grease, in another aspect the invention maintains a heat source within close proximity to the assembly. The heat source keeps the components of the low volume flow above their respective melting points thus preventing coagulation of solids within the main flow channel.
In a preferred embodiment, the heat is provided by hot water flowing into the assembly. The hot water enters the assembly through an entry port which is upstream of the auxiliary exit port. The flow of hot water may be regulated by a solenoid valve. The heat source may also be an electrical heater.
In the process of the invention, the cooking appliance is periodically purged with a high volume flow of water to clear residue. This flow of water is drained through a drain assembly connected to the cooking appliance. Between the purgings, effluent from the cooking appliance drains into the drain assembly and then, within the drain assembly, is diverted from the main flow path used by the high volume flow.
In a preferred embodiment of this process, the drain assembly is heated. The heat will maintain the cooking effluent in a liquid state so that it will flow and not obstruct the main flow path of the drain assembly. The heat is preferably provided by flowing hot water into the drain assembly. The flow of hot water may be regulated by a solenoid valve, or other suitable means, before it is introduced into the drain assembly,
It is preferable to divert the cooking effluent into an accumulator attached to the drain assembly. Subsequently, the effluent may be conducted into a grease/water separator in order for the grease and water components of that effluent to be properly disposed of. The effluent can be conducted to such a grease/water separator by using a suction pump in connection with the accumulator.
It should be understood that the apparatus, and the associated process, can be used with cooking appliances other than combination ovens, such as rotisserie ovens and the like.
These and other aspects of the present invention will become apparent to those skilled in the art after reading the following description of the preferred embodiment when considered with the drawings.